Government agencies said the move was planned already, but it may have been quickened by the pollution incident.
An explosion at a chemical plant Nov. 13 sent 100 tons of benzene, a cancer-causing chemical, into China's Songhua River.
The city of Harbin shut off water to its residents for days as the chemical flowed downstream. Other Chinese cities are preparing to take similar action as are Russian towns and cities on the river or its tributaries.
The incident took place in Jilin province and officials there are blamed for not acting quick enough.